-LRB- CNN -RRB- -- A police officer jailed on a first-degree murder charge in a two-state shooting rampage was on his computer at the time of shootings and could not have committed them , prosecutors said Tuesday evening .

Brian E. Dorian , 37 , was to be released on his own recognizance Tuesday night , and charges against him will be formally dismissed Wednesday , Will County State 's Attorney James W. Glasgow announced .

`` I feel horrible that Brian Dorian went through this , '' said Glasgow , adding that evidence at the time and identification in lineups merited the charges . `` At no time did we stop looking for exculpatory evidence . ''

A forensic analysis of Dorian 's home computer and its activity put Dorian at home at the time of the shootings , authorities said . The officer also told them he was watching sports programs and using e-mail .

John Dorian , the officer 's father , told CNN affiliate WLS he was `` relieved '' and `` never doubted his son . ''

Police now are looking at other leads in the shootings .

Earlier in the day , Dorian appeared in court via a hookup from the Will County Jail . He did not speak but his attorney entered a not guilty plea , WLS reported .

Several friends and relatives wore T-shirts bearing the message `` Free Brian . ''

`` There 's an innocent man sitting behind bars and somebody else is running around out there knowing that he got away with it . It 's not fair , '' Jill Aggen , a friend of Dorian , told WLS . `` No doubt in my mind . He 's not capable of it . ''

Dorian , an officer with the Lynwood Police Department , was arrested Friday in the killing of one person and the wounding of three others in the spree , which occurred south of Chicago , Illinois .

He was held on a probable cause warrant , and bail was set at $ 2.5 million .

Dorian , who according to WLS has been on medical leave for an injured shoulder the past year , was taken into custody Friday at his residence , said authorities .

The shootings began about 10:30 a.m. October 5 at a construction site near Beecher , Illinois . The gunman killed one worker at the site and wounded two others , police have said .

An hour later and about 10 miles away in Lowell , Indiana , authorities believe the same gunman opened fire again -- this time on a local farmer . Keith Dahl was shot in the left shoulder , arm and elbow , and then was robbed .

Dahl told Lake County -LRB- Indiana -RRB- Sheriff 's Detective Robert Martinez that the gunman approached him on his farm and started a conversation about bees before beginning to shoot .

The gunman was believed to be using a revolver -- possibly a Colt .38 - caliber or .357 Magnum -- because no shell casings were found at either scene , Lake County Sheriff Rogelio `` Roy '' Dominguez said .

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Police officer to be freed in Illinois , Indiana shootings

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Analysis of computer shows he was at home at time of crimes

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Brian E. Dorian was being held on $ 2.5 million bail

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One person was killed and three wounded in shootings south of Chicago